[petsc-users] Insufficient memory when using GMRES + Boomeramg

[Matthew Knepley]

On Wed, Mar 26, 2014 at 10:42 AM, TAY wee-beng <zonexo at gmail.com> wrote:

>  On 26/3/2014 11:22 PM, Matthew Knepley wrote:
>
>  On Wed, Mar 26, 2014 at 9:59 AM, TAY wee-beng <zonexo at gmail.com> wrote:
>
>> Hi,
>>
>> I am running a CFD solver. The Poisson eqn was originally solved using
>> HYPRE's geometric multigrid.
>>
>
>  Is this on a structured grid?
>
>
> Yes.
>

Then you can replicate the Hypre structured MG with the PCMG, and it can be
lighter memory than GAMG. You
will need to code the problem in the style of SNES ex5, which is a Poisson
for which geometric MG works from
the command line.

  Thanks,

     Matt


>     Matt
>
>
>> Recently, I tested it with Boomeramg as the preconditioner and GMRES as
>> the ksp solver. There's a 20% increase in speed.
>>
>> However, when I increased the grid resolution, I got the out of memory
>> error. Changing the solver back to HYPRE solved the problem.
>>
>> So does GMRES  + Boomeramg used more memory than other solvers? Are there
>> alternatives?
>>
>> Thank you.
>>
>> --
>> Yours sincerely,
>>
>> TAY wee-beng
>>
>>
>
>
>  --
> What most experimenters take for granted before they begin their
> experiments is infinitely more interesting than any results to which their
> experiments lead.
> -- Norbert Wiener
>
>
>


-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
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